always answer yes to default redis values (#491)

Author: Daniel Hansson

static/redis-server-ubuntu16.sh

@@ -45,7 +45,7 @@ sudo apt install -q -y \
     php-pear
 
 # Install PHPmodule
-if ! pecl install -Z redis
+if ! yes '' | pecl install -Z redis
 then
     msg_box "PHP module installation failed"
     exit 1